Decades-old question: Is anti-bacterial soap safe?

It’s a chemical that’s been in U.S. households for more than 40 years, from the body wash in your bathroom shower to the knives on your kitchen counter to the bedding in your baby’s basinet.

But federal health regulators are just now deciding whether triclosan — the germ-killing ingredient found in an estimated 75 percent of anti-bacterial liquid soaps and body washes sold in the U.S. — is ineffective, or worse, harmful.

The U.S. Food and Drug Administration is planning to deliver a review this year of whether triclosan is safe. The ruling, which will determine whether triclosan continues to be used in household cleaners, could have implications for a $1 billion industry that includes hundreds of anti-bacterial products from toothpaste to toys.

The agency’s review comes amid growing pressure from lawmakers, consumer advocates and others who are concerned about the safety of triclosan. Recent studies of triclosan in animals have led scientists to worry that it could increase the risk of infertility, early puberty and other hormone-related problems in humans.

“To me it looks like the risks outweigh any benefit associated with these products right now,” said Allison Aiello, professor at the University of Michigan’s School of Public Health. “At this point, it’s just looking like a superfluous chemical.”

The concerns over triclosan offer a sobering glimpse at a little-known fact: Many chemicals used in everyday household products have never been formally approved by U.S. health regulators. That’s because many germ-killing chemicals were developed decades ago before there were laws requiring scientific review of cleaning ingredients.

The controversy also highlights how long it can take the federal government to review the safety of such chemicals. It’s not uncommon for the process to drag on for years, since regulators must review volumes of research and take comments from the public on each draft.

In the case of triclosan, Congress passed a law in 1972 requiring that the FDA set guidelines for dozens of common anti-bacterial chemicals found in over-the-counter soaps and scrubs. The guidelines function like a cookbook for manufacturers, detailing which chemicals can be used in what products, and in what amounts.

In 1978, the FDA published its first tentative guidelines for chemicals used in liquid hand soaps and washes. The draft stated that triclosan was “not generally recognized as safe and effective,” because regulators could not find enough scientific research demonstrating its safety and effectiveness.

The FDA published several drafts of the guidelines over the years, but the agency never finalized the results. So, companies have not had to remove triclosan from their products.

Meanwhile, the agency did approve triclosan for use in Colgate’s Total toothpaste in 1997, after Colgate-Palmolive Co. submitted data showing that the ingredient helped fight gingivitis.

Then, last summer, the FDA said its review of triclosan would be complete by late 2012. That target date then slipped to February, which has also come and gone. But pressure on the agency from outside critics didn’t let up.

In March, a federal appeals court said a lawsuit by the nonprofit Natural Resources Defense Council aimed at forcing the FDA to complete its review could move forward. A three-judge panel reinstated the 2010 lawsuit, which had been tossed out by a lower court, saying the nonprofit group presented evidence that triclosan could potentially be dangerous.

Now, four decades after it was charged with reviewing triclosan, the FDA is planning to complete its review. FDA spokeswoman Stephanie Yao said evaluating triclosan and other anti-bacterial agents is “one of the highest priorities” for the agency, but did not offer an explanation for the delay.

The FDA’s website currently states that “the agency does not have evidence that triclosan in antibacterial soaps and body washes provides any benefit over washing with regular soap and water.”

The American Cleaning Institute, a soap and detergent trade organization, says it has provided reams of data to FDA showing that triclosan is both safe and effective.

“Triclosan is one of the most reviewed and researched ingredients used in consumer and health care products,” says Brian Sansoni, a spokesman for the group, whose members include Colgate-Palmolive and Henkel Consumer Goods Inc., maker of Dial soap.

While it can take years for the government to make rules, members of Congress say there is little precedent for the FDA’s four-decade review of triclosan.

“When FDA first started evaluating the rules governing triclosan’s use, Richard Nixon was still president,” said Rep. Edward Markey, D-Mass, who asked the FDA to take a closer look at triclosan in 2010 after the European Union banned the chemical from products that come into contact with food.

“Science has evolved, and so should FDA’s regulations guiding the use of this chemical in consumer products,” he says.

U.S. scientists agree that the FDA’s review is overdue. The Endocrine Society, a group of doctors and scientists who specialize in the hormone system, flagged triclosan four years ago as an ingredient that alters levels of thyroid hormones and reproductive hormones like testosterone and estrogen.